Synthesis of C-substituted t-BuNH-8,9-R,R '-nido-7,8,9-C3B8H9 (R,R ' = H, H;MeH;Me,Me;Ph,H and Ph,Ph) tricarbollide compounds and their tautomeric conversions. Effect of substituents on tautomeric equilibria between neutral and zwitterionic forms
2010
Abstract
The tautomeric behaviour of individual compounds is therefore strongly affected by the nature of the substituent, as assessed via NMR spectroscopy in terms of tautomerisation constants K-T = C-Z2/C-N2 (where C-Z2 and C- N2 are equilibrium concentrations of Z2 and N2 forms in a given solvent). Individual tautomers were characterised by B-11 and H-1 NMR spectroscopy and the structure of the monomethylated N2b tautomer was determined by an X-ray diffraction study.